Custom toolbar isn't working properly, help?

Hi. I tried making a toolbar but for some reason, it didn't add the tool. In line 63, it's not changing nil to a tool or printing. Also, no errors in the output

game.StarterGui:SetCoreGuiEnabled(Enum.CoreGuiType.Backpack,false)

-- Tables and vars
local num = {

    '1',
    '2',
    '3',
    '4',
    '5',
    '6',
    '7',
    '8',
    '9',
}

local numinwords = {

    'One',
    'Two',
    'Three',
    'Four',
    'Five',
    'Six',
    'Seven',
    'Eight',
    'Nine',
}

local tools = {
    One = nil ,
    Two = nil ,
    Three = nil ,
    Four = nil ,
    Five = nil ,
    Six = nil ,
    Seven = nil ,
    Eight = nil ,
    Nine = nil ,

}

local uis = game:GetService('UserInputService')

local plr = game.Players.LocalPlayer

local backpack = game.Players.LocalPlayer:WaitForChild('Backpack')

local frame = script.Parent

local char = plr.Character


for i, v in pairs(backpack:GetChildren()) do
    tools[i] = v
end
--Events
backpack.ChildAdded:Connect(function(tool)
    print('ok')
    for i, v in pairs(tools) do

        if v == nil then
            print('ok2') -- It's not printing 'ok2'
            v = tool

        end
    end

    for i, v in pairs(tools) do
        print(tostring(v))
    end

end)
backpack.ChildRemoved:Connect(function(tool)
    print('ok')
    for i, v in pairs(tools) do
        if v == tool then
            v = nil -- It's not changing it to nil when removed

        end
    end

    for i, v in pairs(tools) do
        print(tostring(v))
    end
end)


for i, v in pairs(frame:GetChildren()) do
    if v:IsA('ImageButton') then
        print('ok')
        uis.InputBegan:Connect(function(input)

            if input.KeyCode == Enum.KeyCode[v.Name] then
                print('ok')

                if tools[v.Name] ~= nil then

                    char.Humanoid:UnequipTool()
                    char.Humanoid:EquipTool(tools[v.Name])
                end
            end

        end)
    end
end


for i, v in pairs(frame:GetChildren()) do
    if v:IsA('ImageButton') then
        v.MouseButton1Click:Connect(function()
                if tools[v.Name] ~= nil then
                    char.Humanoid:UnequipTool()
                    char.Humanoid:EquipTool(tools[v.Name])
                end


        end)
    end
end

Any help/suggestion is appreciated.